Japanese police said they arrested at dawn on Friday a man who barricaded himself on a farm in the center of the country after four people, two women and two policemen, were killed in an attack carried out with a knife and a firearm.
The Nagano Prefectural police chief said at a televised news conference that the suspect hid in his home after shooting two officers who arrived at the scene after a report of a woman had been stabbed.
He said the suspect apparently used a hunting rifle in the shooting.
NHK said the suspect was the son of the head of the Nagano City Council in Nagano Prefecture.
Police Chief Iwao Koyama said the officers and the woman were taken to hospital and declared dead within hours, saying: "This is a heinous crime that has caused great fear among the residents of the area and the community at large."
The two policemen killed were Yoshiki Tamai, 46, and Taku Ikochi, 61.
Rare accident
An elderly woman also died after an apparent knife attack, and media said she had been lying on the floor outside the house since Thursday evening and was unable to be reached by police.
Police detained the man at around 4:30 a.m. local time on Friday (19:30 GMT), about 12 hours after the emergency services first called, media reported. Koyama said he was arrested on suspicion of killing one of the officers.
Shootings are rare in Japan, where gun ownership is subject to strict controls and those seeking to own a gun must be subject to strict scrutiny.
The head of the Public Safety Committee said in a separate statement that the suspect had a license for a hunting rifle.
Koyama said the suspect's mother and another relative were at home with him but managed to escape.
The motive for the incident is not yet known.